MPO and triple-A syndrome: While the mechanism underlying the role of Prdx1 in AAA is unknown, human studies have shown that the serum levels of Prdx1, which are increased in AAA patients [81], are positively correlated with the biomarkers plasmin-antiplasmin and myeloperoxidase and the diameter of AAA, suggesting that Prdx1 may be used as biomarker of AAA [81].